This invention relates to miniature two degree of freedom fluid bearing angular rate sensors for use primarily in tactical applications, i.e. for inertially guiding a missile or the like from launch to target.
Angular rate sensors, for the purposes described must be small, rugged and inexpensive to manufacture. For purposes of example, specifications for a particular two degree of freedom tactical angular rate sensor require the instrument to provide two axes of angular rate information in a package one inch in diameter and one and one-quarter inches in length. The instrument must be designed for constant angular rates up to 300 degrees per second. The sensor rotor bearing suspension must be able to sustain 40 g's of linear acceleration without degradation of performance. To best serve the purposes intended, the sensor should have a minimum number of components.
The present invention achieves the aforementioned requirements by featuring a miniature tactical angular rate sensor having a spherical hydrodynamic fluid bearing rotor component, a permanent magnet motor/torquer component and an optical pick-off component. The arrangement is such that each component can be preassembled as a sub-assembly, tested and stocked for final assembly, the same being recognized as advantageous.